A variety of fan systems have been made and used over the years in a variety of contexts. For instance, various ceiling fans are disclosed in U.S. Pat. No. 7,284,960, entitled “Fan Blades,” issued Oct. 23, 2007, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 6,244,821, entitled “Low Speed Cooling Fan,” issued Jun. 12, 2001, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 6,939,108, entitled “Cooling Fan with Reinforced Blade,” issued Sep. 6, 2005, the disclosure of which is incorporated by reference herein; U.S. Pub. No. 2008/0008596, entitled “Fan Blades,” published Jan. 10, 2008, the disclosure of which is incorporated by reference herein; and U.S. Provisional Patent Application Ser. No. 61/034,254, entitled “Ceiling Fan System with Brushless Motor,” filed Mar. 6, 2008, the disclosure of which is incorporated by reference herein. Alternatively, any other suitable fans may be used in conjunction with embodiments described herein.
The outer tip of a fan blade or airfoil may be finished by the addition of an aerodynamic tip or winglet. Merely exemplary winglets are described in U.S. Pat. No. 7,252,478, entitled “Fan Blade Modifications,” issued Aug. 7, 2007, the disclosure of which is incorporated by reference herein; U.S. Pub. No. 2008/0014090, entitled “Cuffed Fan Blade Modifications,” published Jan. 17, 2008, the disclosure of which is incorporated by reference herein; and U.S. Pub. No. 2008/0213097, entitled “Angled Airfoil Extension for Fan Blade,” published Sep. 4, 2008, the disclosure of which is incorporated by reference herein. Other suitable structures that may be associated with an outer tip of an airfoil or fan blade will be apparent to those of ordinary skill in the art in view of the teachings herein. Alternatively, the outer tip of an airfoil or fan blade may be simply closed, or may lack any similar structure at all.
The interface of a fan blade and a fan hub may also be provided in a variety of ways. For instance, an interface component is described in U.S. Non-Provisional patent application Ser. No. 12/233,783, entitled “Aerodynamic Interface Component for Fan Blade,” filed Sep. 19, 2008, the disclosure of which is incorporated by reference herein. Alternatively, the interface of a fan blade and a fan hub may include any other component or components, or may lack any similar structure at all.
Fans may also include a variety of mounting structures. For instance, a fan mounting structure is disclosed in U.S. Non-Provisional patent application Ser. No. 12/203,960, entitled “Ceiling Fan with Angled Mounting,” filed Sep. 4, 2008, the disclosure of which is incorporated by reference herein. In addition, a fan may include sensors or other features that are used to control, at least in part, operation of a fan system. For instance, such fan systems are disclosed in U.S. Non-Provisional patent application Ser. No. 12/249,086, entitled “Ceiling Fan with Concentric Stationary Tube and Power-Down Features,” filed Oct. 10, 2008, the disclosure of which is incorporated by reference herein; and U.S. Non-Provisional patent application Ser. No. 12/336,090, entitled “Automatic Control System and Method to Minimize Oscillation in Ceiling Fans,” filed Dec. 16, 2008, the disclosure of which is incorporated by reference herein. Alternatively, any other suitable mounting structures and/or fan systems may be used in conjunction with embodiments described herein.
The effectiveness of very large, High Volume/Low Speed (“HVLS”) ceiling fans as a component of a climate control system in buildings may be readily observed, such as in warm weather when the fans are either used alone or in conjunction with air conditioning, and in winter when they are used in conjunction with a heating system. In the absence of such fans in some settings, natural convection may cause the air to stratify, with the warmest layers at the top adjacent to the roof and the coolest layers at the floor. This may be a particularly undesirable condition in winter, when occupants at floor level may desire heat, and high temperatures just below the roof may increase the rate of thermal loss through the roof and decrease energy efficiency.
A primary function of an HVLS fan in such an environment, particularly in winter months when the HVLS fan is used in conjunction with a heating system, may be to maintain a substantially uniform air temperature throughout the enclosed space by blending the heated air from the upper part of the space with the cooler air closer to the floor. A comfortable and energy-efficient condition may be maintained when the speed of the fan is controlled so that there is just enough air movement to maintain uniform air temperature without excessive speed that might create undesirable drafts. In practice, this condition may be only approximated in many situations. For instance, the speed of the fan may be controlled either manually (e.g., by a control operated by a person at floor level, etc.), or automatically (e.g., by coupling the fan to the controls of the heating system, etc.). In manual operation, the fan may be controlled on the basis of the operator's subjective sense of comfort; and in heating-coupled automatic operation, it may be responsive to room temperature. However, such bases of control may not necessarily provide a substantially uniform temperature throughout the space.
While a variety of systems and techniques have been made and used to control fans and fan systems, it is believed that no one prior to the inventor has made or used the invention recited in the appended claims.
Reference will now be made in detail to various embodiments of the invention, examples of which are illustrated in the accompanying drawings. To the extent that specific dimensions are shown in the accompanying drawings, such dimensions should be regarded as merely illustrative and not limiting in any way. Accordingly, it will be appreciated that such dimensions may be varied in any suitable way.